Otto zwietusck



(No Model.)

I O. ZWIETUSGH.

i. FILTBRING MATERIAL.

1 No. 898,110. Patented Peb. 19, 1889.

N. PETERS4 PhuwLimngmplmr. Whingml Dv C.

'nite quantity o'iifro ziviEruscI-, or MILWAUKEE, Wisconsin.

FILTERING MATERIAL.,

SPECIFICATION forming part of Letters Patent No. 398,110, dated February 19, 1889.

Application filed July 16, 1888. Serial No. 280,085. (No specimens.)

To @ZZ whom it 71mg/ concern: l Be it known that I, OTTo.ZW1E'rUscH,a citil zen of the United States, residing' at Milwaul kee, in the county of Milwaukee and State of I lVisconsin, have invented a new and useful i Improvement in Filtering` Material, of which l the following is a specification. My invent-ion relates to a filtering' nialerial l t'or use i n filters t'or general purposes, but pari ticularl y for the .liltration oi' beer; and my obl jectis to produce an article ot' .filtering` mal terial so prepared as to be easy of transportation, always ready for use, and not liable to spoil with keeping, and at the same time to have it divided into portiony ef 4:lg-fin;ielymeasured quantity. A e

lo prepare the article, I lake wood liber i ground in a wet state direct from the mill, or in a dry state in a form resembling` blottingpaper or pasteboard, and prepare and cleanse it by boiling with muriat-ic acid or caustic soda to get rid of all substances which may prove destructive to or have an injurious et'- i fectupon beer. Aft-crithasbeenwellcleansed l and prepared I put it into a press in separate l and equally-measured quantities, and by expressing the `free Water cause each separate portion to form a block ot' such shape as may i be desired, after which I dry it by means of l heat or simple exposure to the atmosphere. By pressing the material into blocks of defiproperly regulated I am able to cause each block to constitute the requisite quantity vfor one iiltering-layer or an aliquot part thereof. It will thus be seen that the element of thickness is an impor-tam one in connection with my invention. i The drawing represents ir: perspective a block of my filtering material Ain one ot' the l most convenient forms into which it can be 4o compressed-namely, in the form of a disk, A, an inch, or thereabout, in thickness and of such diameter as to constitute the proper quan ti ty.

For use the block oi' pressed and dried filtering' material is made into a pulp with water and put into the filter. IIeretofore such lilterin material has been prepared with salieylic acidl and alcohol with a view to preserving it; but in this case it is necessary to keep the material in a moist state, and it easily becomes spoiled by age or on account of evaperation of the alcohol. The moist condition, moreover, greatly increases the weight and causes considerable trouble and expense in the matter of transportation. Besides this, the fact that the degree of moisture is not uniform, but varies materially at different times and under different conditions, renders it very difiicult to judge with any degree of accuracy as io the quantities to be used for the filtering-layers.

On the other hand, by as above described and preserving itin a dry state it remains in goed condition for any 65 length of time, besides beingl of light weight in transportation and always yielding a certain and distinct quantity for use.

What I claim as new,l and desire to secure by Letters Patent, isp As a new article ot manufacture for filtering purl'ioses, a compressed block of comminuted and pu ri lied wood fiber, sul'istant-ially as described.

formingl my artiele ')TTO Z lfVIETYSC H. In presence ol'-w .loI-IN G. HiRsoH, HENRY SOHINZ. 

